/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    Associator.java
 *    Copyright (C) 1999-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.associations;

import java.io.Serializable;
import java.util.Enumeration;
import java.util.Vector;

import weka.core.Capabilities;
import weka.core.CapabilitiesHandler;
import weka.core.CapabilitiesIgnorer;
import weka.core.CommandlineRunnable;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.SerializedObject;
import weka.core.Utils;

/**
 * Abstract scheme for learning associations. All schemes for learning
 * associations implemement this class
 *
 * @author Eibe Frank (eibe@cs.waikato.ac.nz)
 * @version $Revision$
 */
public abstract class AbstractAssociator implements Cloneable, Associator, Serializable, CapabilitiesHandler, CapabilitiesIgnorer, OptionHandler, CommandlineRunnable {

    /** for serialization */
    private static final long serialVersionUID = -3017644543382432070L;

    /** Whether capabilities should not be checked */
    protected boolean m_DoNotCheckCapabilities = false;

    /**
     * Returns an enumeration describing the available options.
     *
     * @return an enumeration of all the available options.
     */
    @Override
    public Enumeration<Option> listOptions() {
        Vector<Option> newVector = Option.listOptionsForClassHierarchy(this.getClass(), AbstractAssociator.class);

        return newVector.elements();
    }

    /**
     * Parses a given list of options.
     *
     * @param options the list of options as an array of strings
     * @throws Exception if an option is not supported
     */
    @Override
    public void setOptions(String[] options) throws Exception {
        Option.setOptionsForHierarchy(options, this, AbstractAssociator.class);
    }

    /**
     * Gets the current settings of the associator
     *
     * @return an array of strings suitable for passing to setOptions
     */
    public String[] getOptions() {
        Vector<String> options = new Vector<String>();
        for (String s : Option.getOptionsForHierarchy(this, AbstractAssociator.class)) {
            options.add(s);
        }
        return options.toArray(new String[0]);
    }

    /**
     * Returns the tip text for this property
     * 
     * @return tip text for this property suitable for displaying in the
     *         explorer/experimenter gui
     */
    public String doNotCheckCapabilitiesTipText() {
        return "If set, associator capabilities are not checked before associator is built" + " (Use with caution to reduce runtime).";
    }

    /**
     * Set whether not to check capabilities.
     * 
     * @param doNotCheckCapabilities true if capabilities are not to be checked.
     */
    public void setDoNotCheckCapabilities(boolean doNotCheckCapabilities) {

        m_DoNotCheckCapabilities = doNotCheckCapabilities;
    }

    /**
     * Get whether capabilities checking is turned off.
     * 
     * @return true if capabilities checking is turned off.
     */
    public boolean getDoNotCheckCapabilities() {

        return m_DoNotCheckCapabilities;
    }

    /**
     * Creates a new instance of a associator given it's class name and (optional)
     * arguments to pass to it's setOptions method. If the associator implements
     * OptionHandler and the options parameter is non-null, the associator will have
     * it's options set.
     *
     * @param associatorName the fully qualified class name of the associator
     * @param options        an array of options suitable for passing to setOptions.
     *                       May be null.
     * @return the newly created associator, ready for use.
     * @exception Exception if the associator name is invalid, or the options
     *                      supplied are not acceptable to the associator
     */
    public static Associator forName(String associatorName, String[] options) throws Exception {

        return (Associator) Utils.forName(Associator.class, associatorName, options);
    }

    /**
     * Creates a deep copy of the given associator using serialization.
     *
     * @param model the associator to copy
     * @return a deep copy of the associator
     * @exception Exception if an error occurs
     */
    public static Associator makeCopy(Associator model) throws Exception {
        return (Associator) new SerializedObject(model).getObject();
    }

    /**
     * Creates copies of the current associator. Note that this method now uses
     * Serialization to perform a deep copy, so the Associator object must be fully
     * Serializable. Any currently built model will now be copied as well.
     *
     * @param model an example associator to copy
     * @param num   the number of associators copies to create.
     * @return an array of associators.
     * @exception Exception if an error occurs
     */
    public static Associator[] makeCopies(Associator model, int num) throws Exception {

        if (model == null) {
            throw new Exception("No model associator set");
        }
        Associator[] associators = new Associator[num];
        SerializedObject so = new SerializedObject(model);
        for (int i = 0; i < associators.length; i++) {
            associators[i] = (Associator) so.getObject();
        }
        return associators;
    }

    /**
     * Returns the Capabilities of this associator. Maximally permissive
     * capabilities are allowed by default. Derived associators should override this
     * method and first disable all capabilities and then enable just those
     * capabilities that make sense for the scheme.
     *
     * @return the capabilities of this object
     * @see Capabilities
     */
    public Capabilities getCapabilities() {
        Capabilities defaultC = new Capabilities(this);
        defaultC.enableAll();

        return defaultC;
    }

    /**
     * runs the associator with the given commandline options
     * 
     * @param associator the associator to run
     * @param options    the commandline options
     */
    public static void runAssociator(Associator associator, String[] options) {
        try {
            if (associator instanceof CommandlineRunnable) {
                ((CommandlineRunnable) associator).preExecution();
            }
            System.out.println(AssociatorEvaluation.evaluate(associator, options));
        } catch (Exception e) {
            if ((e.getMessage() != null) && (e.getMessage().indexOf("General options") == -1))
                e.printStackTrace();
            else
                System.err.println(e.getMessage());
        }
        try {
            if (associator instanceof CommandlineRunnable) {
                ((CommandlineRunnable) associator).postExecution();
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    /**
     * Perform any setup stuff that might need to happen before commandline
     * execution. Subclasses should override if they need to do something here
     *
     * @throws Exception if a problem occurs during setup
     */
    @Override
    public void preExecution() throws Exception {
    }

    /**
     * Execute the supplied object. Subclasses need to override this method.
     *
     * @param toRun   the object to execute
     * @param options any options to pass to the object
     * @throws Exception if a problem occurs
     */
    @Override
    public void run(Object toRun, String[] options) throws Exception {
        if (!(toRun instanceof Associator)) {
            throw new IllegalArgumentException("Object to run is not an instance of Associator!");
        }

        preExecution();
        runAssociator((Associator) toRun, options);
        postExecution();
    }

    /**
     * Perform any teardown stuff that might need to happen after execution.
     * Subclasses should override if they need to do something here
     *
     * @throws Exception if a problem occurs during teardown
     */
    @Override
    public void postExecution() throws Exception {
    }
}
